This invention relates to a surface winder for winding a web into rolls or logs. More particularly, the invention relates to an infeed mechanism for feeding cores axially into the winder and for moving the cores toward the winding rolls of the winder.
Winders, also called rewinders, are used to convert large parent rolls of paper into retail sized rolls of bathroom tissue and paper towels. Two types of rewinders are commonly usedxe2x80x94center rewinders and surface rewinders. Center rewinders are described, for example, in U.S. Reissue Pat. No. 28,353 and wind the web on a core which is rotated by a mandrel. Surface rewinders are described, for example, in U.S. Pat. Nos. 4,723,724 and 5,104,055 and wind the web on a core which is rotated by a three roll cradle.
Before the web is wound on a core, glue is applied to the core so that the leading edge of the web adheres to the core to begin the winding process. It is important to be able to maintain the position of the glue accurately relative to the leading edge of the web so that the web is transferred to the core without undesirable wrinkling or folding of the web.
It is also desirable to apply the glue to the core and to position the core to begin the winding process as quickly as possible so that the core infeed process does not limit the recycle speed of the winder.
The invention provides a core infeed mechanism which feeds cores in an axial direction into the winder while a stripe of glue is applied to each core. The position of the glue stripe is accurately maintained by the engagement between the core and the core drive mechanism and by opposed core guides which hold the core as the core is inserted. After the core is inserted between the core guides, one of the core guides rotates out of engagement with the core, and the other core guide rotates the core into engagement with a rotatable core inserter. The core inserter rotates the core to the space between a first winding roll and a stationary plate to begin the winding process. The core is inserted into the space with the glue line accurately positioned relative to the leading end of the web.
The cores are driven axially into the space between the core guides at high speed, and friction between the core guides and the cores maintains the position of the glue stripe and assists in controlling core rebound at the end of core travel. Core rebound may also be restrained by a one-way ratchet rollers on the core guides. The separation of the axial core infeed step from the rotary core insertion step enables high cycle rates to be obtained.